<?php

// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2014 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace Think\Db\Driver;

use Think\Db;

defined('THINK_PATH') or exit();

/**
 * Sqlsrv数据库驱动
 */
class Sqlsrv extends Db {

    protected $selectSql = 'SELECT T1.* FROM (SELECT thinkphp.*, ROW_NUMBER() OVER (%ORDER%) AS ROW_NUMBER FROM (SELECT %DISTINCT% %FIELD% FROM %TABLE%%JOIN%%WHERE%%GROUP%%HAVING%) AS thinkphp) AS T1 %LIMIT%%COMMENT%';

    /**
     * 架构函数 读取数据库配置信息
     * @access public
     * @param array $config 数据库配置数组
     */
    public function __construct($config = '') {
        if (!function_exists('sqlsrv_connect')) {
            E(L('_NOT_SUPPERT_') . ':sqlsrv');
        }
        if (!empty($config)) {
            $this->config = $config;
        }
    }

    /**
     * 连接数据库方法
     * @access public
     */
    public function connect($config = '', $linkNum = 0) {
        if (!isset($this->linkID[$linkNum])) {
            if (empty($config))
                $config = $this->config;
            $host = $config['hostname'] . ($config['hostport'] ? ",{$config['hostport']}" : '');
            $connectInfo = array('Database' => $config['database'], 'UID' => $config['username'], 'PWD' => $config['password'], 'CharacterSet' => C('DEFAULT_CHARSET'));
            $this->linkID[$linkNum] = sqlsrv_connect($host, $connectInfo);
            if (!$this->linkID[$linkNum])
                $this->error(false);
            // 标记连接成功
            $this->connected = true;
            //注销数据库安全信息
            if (1 != C('DB_DEPLOY_TYPE'))
                unset($this->config);
        }
        return $this->linkID[$linkNum];
    }

    /**
     * 释放查询结果
     * @access public
     */
    public function free() {
        sqlsrv_free_stmt($this->queryID);
        $this->queryID = null;
    }

    /**
     * 执行查询  返回数据集
     * @access public
     * @param string $str  sql指令
     * @param array $bind 参数绑定
     * @return mixed
     */
    public function query($str, $bind = array()) {
        $this->initConnect(false);
        if (!$this->_linkID)
            return false;
        //释放前次的查询结果
        if ($this->queryID)
            $this->free();
        N('db_query', 1);
        // 记录开始执行时间
        G('queryStartTime');
        $str = str_replace(array_keys($bind), '?', $str);
        $bind = array_values($bind);
        $this->queryStr = $str;
        $this->queryID = sqlsrv_query($this->_linkID, $str, $bind, array("Scrollable" => SQLSRV_CURSOR_KEYSET));
        $this->debug();
        if (false === $this->queryID) {
            $this->error();
            return false;
        } else {
            $this->numRows = sqlsrv_num_rows($this->queryID);
            return $this->getAll();
        }
    }

    /**
     * 执行语句
     * @access public
     * @param string $str  sql指令
     * @param array $bind 参数绑定
     * @return integer
     */
    public function execute($str, $bind = array()) {
        $this->initConnect(true);
        if (!$this->_linkID)
            return false;
        //释放前次的查询结果
        if ($this->queryID)
            $this->free();
        N('db_write', 1);
        // 记录开始执行时间
        G('queryStartTime');
        $str = str_replace(array_keys($bind), '?', $str);
        $bind = array_values($bind);
        $this->queryStr = $str;
        $this->queryID = sqlsrv_query($this->_linkID, $str, $bind);
        $this->debug();
        if (false === $this->queryID) {
            $this->error();
            return false;
        } else {
            $this->numRows = sqlsrv_rows_affected($this->queryID);
            $this->lastInsID = $this->mssql_insert_id();
            return $this->numRows;
        }
    }

    /**
     * 用于获取最后插入的ID
     * @access public
     * @return integer
     */
    public function mssql_insert_id() {
        $query = "SELECT @@IDENTITY as last_insert_id";
        $result = sqlsrv_query($this->_linkID, $query);
        list($last_insert_id) = sqlsrv_fetch_array($result);
        sqlsrv_free_stmt($result);
        return $last_insert_id;
    }

    /**
     * 启动事务
     * @access public
     * @return void
     */
    public function startTrans() {
        $this->initConnect(true);
        if (!$this->_linkID)
            return false;
        //数据rollback 支持
        if ($this->transTimes == 0) {
            sqlsrv_begin_transaction($this->_linkID);
        }
        $this->transTimes++;
        return;
    }

    /**
     * 用于非自动提交状态下面的查询提交
     * @access public
     * @return boolen
     */
    public function commit() {
        if ($this->transTimes > 0) {
            $result = sqlsrv_commit($this->_linkID);
            $this->transTimes = 0;
            if (!$result) {
                $this->error();
                return false;
            }
        }
        return true;
    }

    /**
     * 事务回滚
     * @access public
     * @return boolen
     */
    public function rollback() {
        if ($this->transTimes > 0) {
            $result = sqlsrv_rollback($this->_linkID);
            $this->transTimes = 0;
            if (!$result) {
                $this->error();
                return false;
            }
        }
        return true;
    }

    /**
     * 获得所有的查询数据
     * @access private
     * @return array
     */
    private function getAll() {
        //返回数据集
        $result = array();
        if ($this->numRows > 0) {
            while ($row = sqlsrv_fetch_array($this->queryID, SQLSRV_FETCH_ASSOC))
                $result[] = $row;
        }
        return $result;
    }

    /**
     * 取得数据表的字段信息
     * @access public
     * @return array
     */
    public function getFields($tableName) {
        $result = $this->query("
            SELECT column_name,data_type,column_default,is_nullable
            FROM   information_schema.tables AS t
            JOIN   information_schema.columns AS c
            ON     t.table_catalog = c.table_catalog
            AND    t.table_schema  = c.table_schema
            AND    t.table_name    = c.table_name
            WHERE  t.table_name = '{$tableName}'");
        $pk = $this->query("SELECT * FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE WHERE TABLE_NAME='{$tableName}'");
        $info = array();
        if ($result) {
            foreach ($result as $key => $val) {
                $info[$val['column_name']] = array(
                    'name' => $val['column_name'],
                    'type' => $val['data_type'],
                    'notnull' => (bool) ($val['is_nullable'] === ''), // not null is empty, null is yes
                    'default' => $val['column_default'],
                    'primary' => $val['column_name'] == $pk[0]['COLUMN_NAME'],
                    'autoinc' => false,
                );
            }
        }
        return $info;
    }

    /**
     * 取得数据表的字段信息
     * @access public
     * @return array
     */
    public function getTables($dbName = '') {
        $result = $this->query("SELECT TABLE_NAME
            FROM INFORMATION_SCHEMA.TABLES
            WHERE TABLE_TYPE = 'BASE TABLE'
            ");
        $info = array();
        foreach ($result as $key => $val) {
            $info[$key] = current($val);
        }
        return $info;
    }

    /**
     * order分析
     * @access protected
     * @param mixed $order
     * @return string
     */
    protected function parseOrder($order) {
        return !empty($order) ? ' ORDER BY ' . $order : ' ORDER BY rand()';
    }

    /**
     * 字段名分析
     * @access protected
     * @param string $key
     * @return string
     */
    protected function parseKey(&$key) {
        $key = trim($key);
        if (!preg_match('/[,\'\"\*\(\)\[.\s]/', $key)) {
            $key = '[' . $key . ']';
        }
        return $key;
    }

    /**
     * limit
     * @access public
     * @param mixed $limit
     * @return string
     */
    public function parseLimit($limit) {
        if (empty($limit))
            return '';
        $limit = explode(',', $limit);
        if (count($limit) > 1)
            $limitStr = '(T1.ROW_NUMBER BETWEEN ' . $limit[0] . ' + 1 AND ' . $limit[0] . ' + ' . $limit[1] . ')';
        else
            $limitStr = '(T1.ROW_NUMBER BETWEEN 1 AND ' . $limit[0] . ")";
        return 'WHERE ' . $limitStr;
    }

    /**
     * 更新记录
     * @access public
     * @param mixed $data 数据
     * @param array $options 表达式
     * @return false | integer
     */
    public function update($data, $options) {
        $this->model = $options['model'];
        $sql = 'UPDATE '
                . $this->parseTable($options['table'])
                . $this->parseSet($data)
                . $this->parseWhere(!empty($options['where']) ? $options['where'] : '')
                . $this->parseLock(isset($options['lock']) ? $options['lock'] : false)
                . $this->parseComment(!empty($options['comment']) ? $options['comment'] : '');
        return $this->execute($sql, $this->parseBind(!empty($options['bind']) ? $options['bind'] : array()));
    }

    /**
     * 删除记录
     * @access public
     * @param array $options 表达式
     * @return false | integer
     */
    public function delete($options = array()) {
        $this->model = $options['model'];
        $sql = 'DELETE FROM '
                . $this->parseTable($options['table'])
                . $this->parseWhere(!empty($options['where']) ? $options['where'] : '')
                . $this->parseLock(isset($options['lock']) ? $options['lock'] : false)
                . $this->parseComment(!empty($options['comment']) ? $options['comment'] : '');
        return $this->execute($sql, $this->parseBind(!empty($options['bind']) ? $options['bind'] : array()));
    }

    /**
     * 关闭数据库
     * @access public
     */
    public function close() {
        if ($this->_linkID) {
            sqlsrv_close($this->_linkID);
        }
        $this->_linkID = null;
    }

    /**
     * 数据库错误信息
     * 并显示当前的SQL语句
     * @access public
     * @return string
     */
    public function error($result = true) {
        $errors = sqlsrv_errors();
        $this->error = '';
        foreach ($errors as $error) {
            $this->error .= $error['code'] . ':' . $error['message'];
        }
        if ('' != $this->queryStr) {
            $this->error .= "\n [ SQL语句 ] : " . $this->queryStr;
        }
        $result ? trace($this->error, '', 'ERR') : E($this->error);
        return $this->error;
    }

}
